Don't show "error opening file" message if the file is currently open in a custom viewer.
Try to re-open a renamed image file just like we do for a renamed text file. This will give the language manager to decide whether we should use a different customer viewer or open it as a text file. An example of this is to rename a svg file as png.
Don't keep the image file open on mac. Instead, select the previously opened text file or show no-editor.
Whenever we nullify editor, we also need to reset _currentlyViewedPath.
Merge pull request #5721 from adobe/rlim/invalid-image-ext

Re-open a file after renaming even if the file is open in a custom viewer.